外文翻譯----離心泵在化工生產(chǎn)的應用

1、<p>　　CENTRIFUGAL PUMP IN CHEMICALPRODUCTIONAPPLICATION</p><p>　　Centrifugal pump in chemical production, this is most widely used because of its performance wide range (including flow, pressure head of

2、 media properties and ShiYing sexual), small volume, simple structure, easy operation, flow uniformity, low malfunction, long service life, CaoZuoFei are lower cost and prominent advantages. </p><p>　　(1)cen

3、trifugal pump principle of work </p><p>　　Centrifugal pump working principle is: centrifugal pump so can turn the water away is because only centrificating. Water pump before work, pump body and feed water f

4、ull line must be cans in vacuum condition, when the impeller fast turns, leaf prompted water quickly spin, spin in the water under the action of the centrifugal force, pump impeller flew in from the water was thrown in t

5、he central part of the impeller, after forming vacuum area. Water in the water atmospheric pressure (or water press</p><p>　　Centrifugal pump is a lot of more phyletic, classification methods common has the

6、following kinds of kind: 1, press the impeller inhaled way points: single suction style centrifugal pump double suction type centrifugal pump. 2, press the impeller number points: single grade centrifugal pump mulfistage

7、 centrifugal pump. 3, according to the structure of impeller points: open impeller centrifugal pump impeller half open centrifugal pump closed impeller centrifugal pump. 4, according to work pressur</p><p>　

8、　(2) basic structure, centrifugal pumps </p><p>　　Centrifugal pump is the basic structure by six parts, it is respectively, pump body, impeller pump shaft, bearing, sealing ring, the stuffing box. </p>

9、<p>　　1, centrifugal pump impeller is higher than the core part, its great strength, speed and a impeller blades of the main function, impeller before assembly through the static balance experiments. Internal and

10、external surface requirements on the impeller of smooth, to reduce water friction losses. </p><p>　　2, the pump body also called pump shell, it is the pump body. Play support fixed effect, and is connected t

11、o install bearing bracket. </p><p>　　3 and the role of pump shaft couplings and motor was borrowed, will connect to the torque motor impeller, so it is the main component of mechanical transmission. </p&g

12、t;<p>　　4, bearing is set in the pump shaft support of pump shaft components, a rolling bearing and sliding bearing two kinds. Rolling bearings use butter as lubricant refueling appropriate to general for 2/3 ~ 3/

13、4 volume too much, too little and can calorific a sound and fever! Sliding bearings use transparent oil for lubricant, refuels to oil level line. Too much oil to leak and drift along the pump shaft, too little bearing an

14、d melech overheating burnt out cause an accident! The water pump operation </p><p>　　5, sealing ring and say minus leak rings. The import and pump impeller shell of the gap between will cause the water pump

15、high-pressure zone within the clearance flow by low pressure area, the influence of the pump, low efficiency, &safe-durable! Gap with the pump impeller had caused moment shell friction wear. In order to reduce leakag

16、e increased reflow resistance, delaying the impeller and pump shell used in the pump housing life, with inner and impeller sealing, department of foreign aid in t</p><p>　　6, stuffing box, mainly by packing

17、rings, packing cone, water storage tube packing gland, composed. The role of the stuffing box is mainly to closed pump shell with the space between the pump shaft, don't let pump of water inside don't flow to the

18、 outside to also don't let the outside air into the pump inside. Always keep the vacuum pump inside! When the pump shaft and packing friction heat water control water to be about to rely on water circle make packing

19、cooling! Maintain normal operation of</p><p>　　(3) centrifugal pump impeller and other components </p><p>　　1. Centrifugal pump impeller </p><p>　　Centrifugal pump impeller is the k

20、ey components. </p><p>　　according to the mechanical structure can be divided into closed, semi-enclosed and open 3 kinds. Closed impeller suitable for conveying clean liquid. Semi-enclosed and open impeller

21、 suitable for conveying containing solid particles of suspending liquid in the efficiency of, this kind of pump low.</p><p>　　Closed and semi-enclosed impeller in operation, leave the impeller's part of

22、high pressure fluid can leak into the impeller and pump shell cavity, between the side because of impeller suction pressure low, liquid at the entrance is liquid in the role of the pressure before and behind impeller to

23、differ, they generate pointing the suction side impeller axial thrust. This force to promote the suction side impeller pump impeller and mobile, cause the contact point of moab shell caused serious damag</p><p

24、>　　according to absorb fluid can be divided into different ways of impeller with single suction style double suction type two kinds, single suction style simple structure, liquid only impeller from one side of the inh

25、alation. Double suction style impeller can simultaneously from impeller symmetry to inhaled liquid, it not only has a greater ability to absorb fluid, and basically eliminate the axial thrust.</p><p>　　(3) o

26、n the impeller blade according to the geometrical shape, can be bent, radial after blade is divided into three, before and after bending due to bend the kinetic energy transfer liquid leaves, so for static pressure can b

27、e used extensively. </p><p>　　2. The centrifugal pump impeller </p><p>　　In order to reduce leave the liquid directly into the pump impeller shell caused by impact energy loss in the impeller an

28、d pump shell, between sometimes device a fixed blade and contain keep-off device. The blade into the pump impeller shell has gradually turned into the liquid flow, make continuous expansion and partial kinetic energy eff

29、ectively converted to static pressure can. Multistage centrifugal pump impeller usually are installed. </p><p>　　The snail shaped pump, impeller blade and the bent on after all can improve kinetic energy to

30、guide the conversion, and therefore can plenum are regarded as turn can device. </p><p>　　3. Shaft sealing device </p><p>　　Because of pump shaft rotation and pump shell stationary, and in the a

31、xis and the contact point of the pump housing must have certain gap. To avoid pump internal high-pressure liquid leakage along the gap, or prevent outside air from the opposite direction into the pump must set within the

32、 shaft seal device. Centrifugal pump shaft sealing device has a filler letter and mechanical (end) seal. Stuffing box is will pump shaft through pump shell ring gap to finish seal, in which loaded soft packing </p>

33、<p>　　(4)the centrifugal pump introduces below several important performance curve.</p><p>　　1, flow - head characteristic curve </p><p>　　It is the basic of centrifugal pump performance

34、curve. Less than 80 than speed centrifugal pump has the characteristics of rise and fall, both sides among (both under convex curved), says hump performance curve. In 80 ~ 150 than speed centrifugal pump has between plai

35、n performance curve. More than 150 RPM centrifugal pump performance curves with steep drop. In general, when flow hours, head is high, with the increase of flow is decreasing. Head </p><p>　　2, flow - power

36、curve </p><p>　　The shaft power increases with the flow, when flow Q = 0, the corresponding shaft power is not equal to zero, and for certain value (about the normal operation of the 60 percent). The power c

37、onsumed mainly by the mechanical loss. This is full of water pump, if long time running, will lead to the temperature rising pump, pump shell, bearing can calorific, serious when may make pump body thermal deformation, w

38、e called "stuffy head", then head for maximum, when water valve gradually opened, the flo</p><p>　　3, flow - efficiency curve </p><p>　　Its curve shape, when flow xiangshan head is equ

39、al, efficiency and equal to zero, with the increase of flow, efficiency, but also gradually increase the efficiency increased to a certain value has decreased, after a high efficiency in highest efficiency point near, ef

40、ficiency is higher, this area is called efficient area. </p><p>　　離心泵在化工生產(chǎn)的應用</p><p>　　離心泵在化工生產(chǎn)中應用最為廣泛，這是由于其具有性能適用范圍廣（包括流量、壓頭及對介質性質的失迎性）、體積小、結構簡單、操作容易、流量均勻、故障少、壽命長、購置費和操作費均較低等突出優(yōu)點。</p>&l

41、t;p>　?。ㄒ唬?、離心泵的工作原理</p><p>　　離心泵的工作原理是：離心泵所以能把水送出去是由于離心力的作用。水泵在工作前，泵體和進水管必須罐滿水行成真空狀態(tài)，當葉輪快速轉動時，葉片促使水很快旋轉，旋轉著的水在離心力的作用下從葉輪中飛去，泵內的水被拋出后，葉輪的中心部分形成真空區(qū)域。水原的水在大氣壓力（或水壓）的作用下通過管網(wǎng)壓到了進水管內。這樣循環(huán)不已，就可以實現(xiàn)連續(xù)抽水。在此值得一提的是：離心

42、泵啟動前一定要向泵殼內充滿水以后，方可啟動，否則將造成泵體發(fā)熱，震動，出水量減少，對水泵造成損壞（簡稱“氣蝕”）造成設備事故！離心泵的種類很多，分類方法常見的有以下幾種方式：1、按葉輪吸入方式分：單吸式離心泵 雙吸式離心泵。2、按葉輪數(shù)目分：單級離心泵 多級離心泵</p><p>　　3、按葉輪結構分：敞開式葉輪離心泵 半開式葉輪離心泵 封閉式葉輪離心泵</p><p>　　4、按工作壓

43、力分：低壓離心泵 中壓離心泵 高壓離心泵。5、按泵軸位置分：臥式離心泵邊 立式離心泵。</p><p>　?。ǘ?、離心泵的基本構造</p><p>　　離心泵的基本構造是由六部分組成的，分別是葉輪，泵體，泵軸，軸承，密封環(huán)，填料函。</p><p>　　1、葉輪是離心泵的核心部分，它轉速高出力大，葉輪上的葉片又起到主要作用，葉輪在裝配前要通過靜平衡實驗。葉輪上的內

44、外表面要求光滑，以減少水流的摩擦損失。</p><p>　　2、泵體也稱泵殼，它是水泵的主體。起到支撐固定作用，并與安裝軸承的托架相連接。</p><p>　　3、泵軸的作用是借聯(lián)軸器和電動機相連接，將電動機的轉距傳給葉輪，所以它是傳遞機械能的主要部件。</p><p>　　4、軸承是套在泵軸上支撐泵軸的構件，有滾動軸承和滑動軸承兩種。滾動軸承使用牛油作為潤滑劑加油

45、要適當一般為2/3～3/4的體積太多會發(fā)熱，太少又有響聲并發(fā)熱！滑動軸承使用的是透明油作潤滑劑的,加油到油位線。太多油要沿泵軸滲出并且漂賤，太少軸承又要過熱燒壞造成事故！在水泵運行過程中軸承的溫度最高在85度一般運行在60度左右，如果高了就要查找原因（是否有雜質，油質是否發(fā)黑，是否進水）并及時處理！</p><p>　　5、密封環(huán)又稱減漏環(huán)。葉輪進口與泵殼間的間隙過大會造成泵內高壓區(qū)的水經(jīng)此間隙流向低壓區(qū)，影響泵

46、的出水量，效率降低！間隙過小會造成葉輪與泵殼摩擦產(chǎn)生磨損。為了增加回流阻力減少內漏，延緩葉輪和泵殼的所使用壽命，在泵殼內緣和葉輪外援結合處裝有密封環(huán)，密封的間隙保持在0.25～1.10mm之間為宜。</p><p>　　6、填料函主要由填料，水封環(huán)，填料筒，填料壓蓋，水封管組成。填料函的作用主要是為了封閉泵殼與泵軸之間的空隙，不讓泵內的水流不流到外面來也不讓外面的空氣進入到泵內。始終保持水泵內的真空！當泵軸與填料

47、摩擦產(chǎn)生熱量就要靠水封管住水到水封圈內使填料冷卻！保持水泵的正常運行。所以在水泵的運行巡回檢查過程中對填料函的檢查是特別要注意！在運行600個小時左右就要對填料進行更換。（三）離心泵的葉輪和其它部件 </p><p><b>　　1．離心泵的葉輪 </b></p><p>　　葉輪是離心泵的關鍵部件。 </p><p>　　(1)按其機械結構

48、可分為閉式、半閉式和開式三種。閉式葉輪適用于輸送清潔液體；半閉式和開式葉輪適用于輸送含有固體顆粒的懸浮液，這類泵的效率低。 </p><p>　　閉式和半閉式葉輪在運轉時，離開葉輪的一部分高壓液體可漏入葉輪與泵殼之間的空腔中，因葉輪前側液體吸入口處壓強低，故液體作用于葉輪前、后側的壓力不等，便產(chǎn)生了指向葉輪吸入口側的軸向推力。該力推動葉輪向吸入口側移動，引起葉輪和泵殼接觸處的摩損，嚴重時造成泵的振動，破壞泵的正常

49、操作。在葉輪后蓋板上鉆若干個小孔，可減少葉輪兩側的壓力差，從而減輕了軸向推力的不利影響，但同時也降低了泵的效率。這些小孔稱為平衡孔。 </p><p>　　(2)按吸液方式不同可將葉輪分為單吸式與雙吸式兩種，單吸式葉輪結構簡單，液體只能從一側吸入。雙吸式葉輪可同時從葉輪兩側對稱地吸入液體，它不僅具有較大的吸液能力，而且基本上消除了軸向推力。 </p><p>　　(3)根據(jù)葉輪上葉片上的幾

50、何形狀，可將葉片分為后彎、徑向和前彎三種，由于后彎葉片有利于液體的動能轉換為靜壓能，故而被廣泛采用。 </p><p><b>　　2．離心泵的導輪 </b></p><p>　　為了減少離開葉輪的液體直接進入泵殼時因沖擊而引起的能量損失，在葉輪與泵殼之間有時裝置一個固定不動而帶有葉片的導輪。導輪中的葉片使進入泵殼的液體逐漸轉向而且流道連續(xù)擴大，使部分動能有效地轉換為

51、靜壓能。多級離心泵通常均安裝導輪。 </p><p>　　蝸牛形的泵殼、葉輪上的后彎葉片及導輪均能提高動能向靜壓能的轉化率，故均可視作轉能裝置。 </p><p><b>　　3．軸封裝置 </b></p><p>　　由于泵軸轉動而泵殼固定不動，在軸和泵殼的接觸處必然有一定間隙。為避免泵內高壓液體沿間隙漏出，或防止外界空氣從相反方向進入泵內，

52、必須設置軸封裝置。離心泵的軸封裝置有填料函和機械（端面）密封。填料函是將泵軸穿過泵殼的環(huán)隙作成密封圈，于其中裝入軟填料（如浸油或涂石墨的石棉繩等）。機械密封是由一個裝在轉軸上的動環(huán)和另一固定在泵殼上的靜環(huán)所構成。兩環(huán)的端面借彈簧力互相貼緊而作相對轉動，起到了密封的作用。機械密封適用于密封較高的場合，如輸送酸、堿、易燃、易爆及有毒的液體。 </p><p>　?。ㄋ模㈦x心泵的幾條重要的性能曲線。</p>

53、;<p>　　1、流量—揚程特性曲線它是離心泵的基本的性能曲線。比轉速小于80的離心泵具有上升和下降的特點（既中間凸起，兩邊下彎），稱駝峰性能曲線。比轉速在80～150之間的離心泵具有平坦的性能曲線。比轉數(shù)在150以上的離心泵具有陡降性能曲線。一般的說，當流量小時，揚程就高，隨著流量的增加揚程就逐漸下降。</p><p><b>　　2、流量—功率曲線</b></p&g

54、t;<p>　　軸功率是隨著流量而增加的，當流量Q=0時，相應的軸功率并不等于零，而為一定值（約正常運行的60％左右）。這個功率主要消耗于機械損失上。此時水泵里是充滿水的，如果長時間的運行，會導致泵內溫度不斷升高，泵殼，軸承會發(fā)熱，嚴重時可能使泵體熱力變形，我們稱為“悶水頭”，此時揚程為最大值，當出水閥逐漸打開時，流量就會逐漸增加，軸功率亦緩慢的增加。</p><p><b>　　3、流量